Genetic characterization of cucumber genetic resources in the NARO Genebank indicates their multiple dispersal trajectories to the East.

KEY MESSAGE: Genotyping-by-sequencing of 723 worldwide cucumber genetic resources revealed that cucumbers were dispersed eastward via at least three distinct routes, one to Southeast Asia and two from different directions to East Asia. The cucumber (Cucumis sativus) is an economically important vegetable crop cultivated and consumed worldwide. Despite its popularity, the manner in which cucumbers were dispersed from their origin in South Asia to the rest of the world, particularly to the east, remains a mystery due to the lack of written records. In this study, we performed genotyping-by-sequencing (GBS) on 723 worldwide cucumber accessions, mainly deposited in the Japanese National Agriculture and Food Research Organization (NARO) Genebank, to characterize their genetic diversity, relationships, and population structure. Analyses based on over 60,000 genome-wide single-nucleotide polymorphisms identified by GBS revealed clear genetic differentiation between Southeast and East Asian populations, suggesting that they reached their respective region independently, not progressively. A deeper investigation of the East Asian population identified two subpopulations with different fruit characteristics, supporting the traditional classification of East Asian cucumbers into two types thought to have been introduced by independent routes. Finally, we developed a core collection of 100 accessions representing at least 93.2% of the genetic diversity present in the entire collection. The genetic relationships and population structure, their associations with geographic distribution and phenotypic traits, and the core collection presented in this study are valuable resources for elucidating the dispersal history and promoting the efficient use and management of genetic resources for research and breeding in cucumber.

A novel and effective method for solving the router nodes placement in wireless mesh networks using reinforcement learning.

Router nodes placement (RNP) is an important issue in the design and implementation of wireless mesh networks (WMN). This is known as an P-hard problem, which cannot be solved using conventional algorithms. Consequently, approximate optimization strategies are commonly used to solve this problem. With heavy node density and wide-area WMNs, solving the RNP problem using approximation algorithms often faces many difficulties, therefore, a more effective solution is necessary. This motivated us to conduct this work. We propose a new method for solving the RNP problem using reinforcement learning (RL). The RNP problem is modeled as an RL model with environment, agent, action, and reward are equivalent to the network system, routers, coordinate adjustment, and connectivity of the RNP problem, respectively. To the best of our knowledge, this is the first study that applies RL to solve the RNP problem. The experimental results showed that the proposed method increased the network connectivity by up to 22.73% compared to the most recent methods.

The therapeutic landscape for COVID-19 and post-COVID-19 medications from genetic profiling of the Vietnamese population and a predictive model of drug-drug interaction for comorbid COVID-19 patients.

Despite the raised awareness of the role of pharmacogenomic (PGx) in personalized medicines for COVID-19, data for COVID-19 drugs is extremely scarce and not even a publication on this topic for post-COVID-19 medications to date. In the current study, we investigated the genetic variations associated with COVID-19 and post-COVID-19 therapies by using whole genome sequencing data of the 1000 Vietnamese Genomes Project (1KVG) in comparison with other populations retrieved from the 1000 Genomes Project Phase 3 (1KGP3) and the Genome Aggregation Database (gnomAD). Moreover, we also evaluated the risk of drug interactions in comorbid COVID-19 and post-COVID-19 patients based on pharmacogenomic profiles of drugs using a computational approach. For COVID-19 therapies, variants related to the response of two causal treatment agents (tolicizumab and ritonavir) and antithrombotic drugs are common in the Vietnamese cohort. Regarding post-COVID-19, drugs for mental manipulations possess the highest number of clinical annotated variants carried by Vietnamese individuals. Among the superpopulations, East Asian populations shared the most similar genetic structure with the Vietnamese population, whereas the African population showed the most difference. Comorbid patients are at an increased drug-drug interaction (DDI) risk when suffering from COVID-19 and after recovering as well due to a large number of potential DDIs which have been identified. Our results presented the population-specific understanding of the pharmacogenomic aspect of COVID-19 and post-COVID-19 therapy to optimize therapeutic outcomes and promote personalized medicine strategy. We also partly clarified the higher risk in COVID-19 patients with underlying conditions by assessing the potential drug interactions.

Morphological, phytochemical and genetic characterization of Centella asiatica accessions collected throughout Vietnam and Laos.

Pennywort (Centella asiatica L.) is commonly grown in the tropical world for its nutritional and medicinal values. Valuable saponins in pennywort are extensively investigated for their anti-tumour activities. The diversity in morphology, phytochemical contents and genetics among pennywort accessions has been extensively studied to identify elite landraces for large-scale production. While pennywort is widely consumed in Vietnam, a systematic characterization of their diverse morphology, secondary metabolites and genetics is lacking. In this work, 26 pennywort accessions were collected across Vietnam and Laos. Their morphological features and yields were characterized under uniform agro-climatic conditions at Hue city in central Vietnam. The highest yield was obtained with HUIB_CA20 (478 g per tray), compared to the lowest yield in HUIB_CA19 (107 g per tray). Furthermore, a range of phytochemical markers, including vitamin C, reducing sugar, carotenoid, tannin, phenolic, flavonoid and saponin contents, were determined. Based on yield, phenolic and flavonoid contents, HUIB_CA20 and HUIB_CA27 were determined to be elite cultivars in this germplasm. Finally, microsatellite analysis was performed to explore the genetic diversity within the germplasm. Using fourteen SSR primer pairs, a total of 47 alleles were identified with 45 alleles (96 %) being polymorphic. These results will be useful for breeding programs aiming to create elite pennywort cultivars with enhanced properties.

The antimicrobial activity and essential oil constituents of the leaves and trunks of Aquilaria banaensis P.H.Hô (Thymelaeceae) from Vietnam.

The aim of the present paper was to report the chemical constituents and antimicrobial activity of essential hydrodistilled from the leaves and trunk of Aquilaria banaensis P.H.Hô (Thymelaeceae) from Vietnam. The essential oils were analysed comprehensively for their constituents by using Gas chromatography coupled with Mass spectrometry (GC/MS). The antimicrobial activity was determined by agar well diffusion and broth microdilution methods. The leaf essential oil comprised mainly of sesquiterpenes while fatty acids constitutes the bulk of the trunk essential oil. The main constituents of the leaf essential oil were ß-caryophyllene (17.11%), α-selinene (10.99%), α-humulene (8.98%), ß-selinene (8.01%), ß-guaiol (6.69%) and ß-elemene (5.65%). However, hexadecanoic acid (48.46%), oleic acid (19.80%) and tetradecanoic acid (5.32%) were the major compounds identified in the trunk essential oil. The trunk essential oil displayed antimicrobial activity against Staphylococcus aureus, with the minimum inhibitory concentration (MIC) value of about 256.0 µg/mL.

Mitophylogeny of Pangasiid Catfishes and its Taxonomic Implications for Pangasiidae and the Suborder Siluroidei.

Pangasiidae (catfish order: Siluriformes) comprises 30 valid catfish species in four genera: Pangasius, Pangasianodon, Helicophagus, and Pseudolais. Their systematics are frequently revised due to the addition of newly described species. Although Pangasiidae is known to be a monophyletic family, the generic and phylogenetic relationships among the taxa are poorly resolved. This study characterized three newly obtained complete mitogenomes of Mekong River catfishes from Vietnam (Pangasius mekongensis, Pangasius krempfi, and Pangasianodon hypophthalmus), as well as the inter-and intrafamilial relationships of the Pangasiidae and catfish families in Siluroidei. The genomic features of their mitogenomes were similar to those of previously reported pangasiids, including all regulatory elements, extended terminal associated sequences (ETAS), and conserved sequence blocks (CSBs) (CSB-1, CSB-2, CSB-3, and CSBs, A to F) in the control region. A comprehensive phylogeny constructed from datasets of multiple 13 PCG sequences from 117 complete mitogenomes of 32 recognized siluriform families established Pangasiidae as monophyletic and a sister group of Austroglanididae. The [Pangasiidae + Austroglanididae] + (Ictaluridae + Cranoglanididae) + Ariidae] clade is a sister to the "Big Africa" major clade of Siluriformes. Furthermore, both phylogenies constructed from the single barcodes (83 partial cox1 and 80 partial cytB, respectively) clearly indicate genus relationships within Pangasiidae. Pangasianodon was monophyletic and a sister to the (Pangasius + Helicophagus + Pseudolais) group. Within the genus Pangasius, P. mekongensis was placed as a sister taxon to P. pangasius. Pangasius sanitwongsei was found to be related to and grouped with Pangasianodon, but in single-gene phylogenies, it was assigned to the Pangasius + Helicophagus + Pseudolais group. The datasets in this study are useful for studying pangasiid systematics, taxonomy and evolution.

Identification and Evaluation of the Growth Promotion of Endophytic Bacteria on in vitro Potato Plants.

<b>Background and Objective:</b> Isolation and investigation of plant growth promoting bacteria on potato plants can provide significant information for the application of beneficial bacteria in potato production. This study aims to isolate and characterize endophytic bacteria isolated from potato roots. In addition, the potential application of endophytes in promoting potato growth under <i>in vitro</i> conditions was also investigated. <b>Materials and Methods:</b> The roots from 15 healthy potato plants were excised and surface sterilized by NaOCl and finally rinsed by sterilized water. The confirmed surface-sterilized roots were then aseptically cut into small fragments and spread onto the isolation media, followed by incubation at 27°C for up to 3 days. Six isolates that showed differences in colony morphology were selected for further investigation. All isolates were screened for IAA production, nitrogen fixation, and phosphate solubilization. <b>Results:</b> Five of the isolates were identified as <i>Bacillus</i> and isolate 30 was identified as <i>Paenibacillus alvei</i>. All isolates exhibited good IAA production. While Iso-27 had no nitrogen fixation activity, Iso-28 showed the highest level of nitrogen fixation activity (3.59 mg L¹), four isolates (Iso-9, Iso-10, Iso-11, Iso-28) could solubilize phosphate, ranging from 49.64 g L¹ to 67.98 mg L¹. After being inoculated with <i>in vitro</i> potato plants, isolates 9, 10, 28, 30, improved the stalk length, root number, fresh mass and dried mass of the potato plants. <b>Conclusion:</b> The four isolates can potentially be applied in <i>in vitro</i> potato culture.

Factors That Influence the Intention of Smallholder Rice Farmers to Adopt Cleaner Production Practices: An Empirical Study of Precision Agriculture Adoption.

Sustainable agriculture is crucial for achieving SDG2 and building a resilient climate-food system. This study provides a nuanced understanding of factors that influence the adoption of precision agriculture technology by Vietnamese smallholder rice farmers as a sustainable agricultural solution. The study's objectives are: (1) to provide a nuanced understanding of factors that influence adoption of precision agriculture technology by Vietnamese smallholder rice farmers; and (2) to identify factors associated with agricultural practice in Vietnam that may impact the adoption of precision agriculture technology. The study conducted 35 semi-structured interviews with smallholder rice farmers and agriculture experts. Data were analyzed using iterative thematic analysis. The Unified Theory of Acceptance and Use of Technology (UTAUT) model was used for empirical analysis. The UTAUT constructs of Performance expectancy, Effort expectancy, Government support, and Social influence were found to be determinants of adoption. Trialability and Observability impact Effort expectancy and Performance expectancy. We also discovered that the performance of agricultural cooperatives and support of lead firms play a crucial role in facilitating agricultural technology adoption by Vietnamese smallholder rice farmers. The results confirm the applicability of UTAUT in defining smallholders' behavioural intention and predicting agricultural technology adoption. The study also provides constructive feedback on the UTAUT model by highlighting the effect of agricultural cooperatives' performance as innovation intermediaries and of the support of lead firms.

Gold nanoshells with magnetic cores and a urea-based receptor for SERS sensing of fluoride anions: experimental and computational study.

The study demonstrates that a combination of plasmonic nanostructures and artificial receptors can be applied for sensing small molecular species. Gold nanoshells containing magnetic cores are used as the SERS-active substrates, which opens the way for the development of multimodal contrast agents with applicability extended to sensing or for the separation of analytes by magnetic solid-phase extraction. Disubstituted ureas forming hydrogen-bonded complexes with certain anions can be employed as molecular sensors. In this case study, gold nanoshells with silica-coated Mn-Zn ferrite cores were prepared by a multistep procedure. The nanoshells were co-functionalized with an N-(4-mercaptophenyl)-N'-(4-nitrophenyl)urea sensor synthesized directly on the gold surface, and with 4-nitrothiophenol, which is adopted as an internal standard. SERS measurements were carried out with acetonitrile solutions of tetrabutylammonium fluoride (Bu4NF) over a concentration range of 10-10-10-1 mol L-1. The spectral response of the sensor is dependent on the fluoride concentration in the range of 10-5-10-1 mol L-1. To investigate further the SERS mechanism, a model sensor, N-(4-bromophenyl)-N'-(4-nitrophenyl)urea, was synthesized and used in Raman spectroscopy with solutions of Bu4NF, up to a molar ratio of 1 : 20. The spectra and the interactions between the sensors and fluoride anions were also studied by extensive DFT computations.

Copy number variations of cytochrome P450 genes in Kinh Vietnamese.

Background: The cytochrome P450 (CYP450) family is well known as a major group of drug metabolizing enzymes. The polymorphism of CYP450 genes is the main factor having an impact on the interindividual difference in drug response, including drug efficacy and drug safety. The single nucleotide polymorphism (SNPs) of Vietnamese Kinh has been widely studied, but information about the copy number variations (CNVs) of other CYP450 genes is still unknown. Objective: To identify the CNV variability of CYP450 in 154 healthy unrelated Kinh Vietnamese, except eCYP2D6, which was previously reported. Methods: Multiplex Ligation-Dependent Probe Amplification (MLPA) was applied for determination of copy number of 10 CYP450 genes. Later, PCR or quantitative PCR (qPCR) was used to confirm the detected CNVs in randomly chosen subjects. Results: Of the 154 subjects, along with CYP2D6, 4 other CYP450 genes showed CNVs including duplications (CYP1B1), deletions (CYP2A6 and CYP2C9), and both duplications and deletions (CYP2E1). Among these, CYP2A6 exhibited the greatest frequency of CNVs compared with other CYP450, in which CYP2A6Del accounted for 11%. Meanwhile, allele CYP2E1Del showed the lowest frequency with only 0.3%. Conclusions: The present study provides new insight into CYP450 CNVs in the Kinh Vietnamese cohort. Our data have contributed to genetic profiling of CYP450 CNVs in Vietnam, which would be helpful for facilitating implementation of pharmacogenetics in drug dosing adjustment in Vietnam.

Management of brain metastasis from rectal cancer using whole­brain radiation therapy followed by bevacizumab and chemotherapy: A case report.

Brain metastases in colorectal cancer are uncommon, which has resulted in a shortage of data concerning their screening and management. Multiple therapeutic modalities with chemotherapy, chemoradiation and targeted therapy, including bevacizumab and cetuximab regimens, have shown promising results. The present study describes the case of a 47-year-old male, diagnosed with T4N2M1 rectal cancer who underwent systemic therapy with modified FOLFOXIRI and cetuximab. The patient achieved a complete clinical response after 12 cycles. Following the discontinuation of cetuximab, the patient was given capecitabine as a maintenance therapy and subsequently developed brain metastasis. The patient received whole-brain radiation therapy (WBRT) followed by a bevacizumab plus FOLFIRI regimen. The patient showed a good response as revealed by cranial magnetic resonance imaging, with a reduction in lesion size and no sign of cerebral edema. In addition, the patient maintained a stable neurological condition for >10 months. These findings suggest that the early detection of brain metastases requires the close monitoring of neurological symptoms. In addition, WBRT followed by bevacizumab and chemotherapy is a potential management plan for brain metastasis from rectal cancer.

Elective spinal surgery in New South Wales adults, 2001-20, by procedure funding type: a cross-sectional study.

OBJECTIVE: To investigate elective rates of spinal fusion, decompression, and disc replacement procedures for people with degenerative conditions, by funding type (public, private, workers' compensation). DESIGN, SETTING: Cross-sectional study; analysis of hospitals admissions data extracted from the New South Wales Admitted Patient Data Collection. PARTICIPANTS: All adults who underwent elective spinal surgery (spinal fusion, decompression, disc replacement) in NSW, 1 July 2001 - 30 June 2020. MAIN OUTCOME MEASURES: Crude and age- and sex-adjusted procedure rates, by procedure, funding type, and year; annual change in rates, 2001-20, expressed as incidence rate ratios (IRRs). RESULTS: During 2001-20, 155 088 procedures in 129 525 adults were eligible for our analysis: 53 606 fusion, 100 225 decompression, and 1257 disc replacement procedures. The privately funded fusion procedure rate increased from 26.6 to 109.5 per 100 000 insured adults (per year: IRR, 1.06; 95% confidence interval [CI], 1.05-1.07); the workers' compensation procedure rate increased from 6.1 to 15.8 per 100 000 covered adults (IRR, 1.04; 95% CI, 1.01-1.06); the publicly funded procedure rate increased from 5.6 to 12.4 per 100 000 adults (IRR, 1.03; 95% CI, 1.01-1.06), and from 10.5 to 22.1 per 100 000 adults without hospital cover private health insurance (IRR, 1.03; 95% CI, 1.01-1.05). The privately funded decompression procedure rate increased from 93.4 to 153.6 per 100 000 people (IRR, 1.02; 95% CI, 1.01-1.03); the workers' compensation procedure rate declined from 19.7 to 16.7 per 100 000 people (IRR, 0.98; 95% CI, 0.96-0.99), and the publicly funded procedure rate did not change significantly. The privately funded disc replacement procedure rate increased from 6.2 per million in 2010-11 to 38.4 per million people in 2019-20, but did not significantly change for the other two funding groups. The age- and sex-adjusted rates for privately and publicly funded fusion and decompression procedures were similar to the crude rates. CONCLUSIONS: Privately funded spinal surgery rates continue to be larger than for publicly funded procedures, and they have also increased more rapidly. These differences may indicate that some privately funded procedures are unnecessary, or that the number of publicly funded procedures does not reflect clinical need.

Dietary intake and occupational status among female youths of Thai Nguyen, Vietnam.

Adolescence is a sensitive transition time that affects rights, roles, and responsibilities in food choice, yet limited evidence exists on dietary intakes during this critical period. This study assessed the food consumption pattern and the adequacy of energy, macronutrient, and micronutrient intakes among female youth belonging to three occupational groups in Vietnam. Dietary intakes were measured for 1001 participants aged 16-22 years using INDDEX24's 24-h recall method. Multivariate regression analyses were conducted to examine differences in diet outcomes among the three occupational groups. Dietary diversity was similar across groups but workers, compared to high school and college students, consumed less baked/grain-based sweets and fast foods, and more soft drinks, other sweets, and processed meat. Two-thirds of the sample showed energy intake lower than the estimated energy requirement, while a substantial percentage had insufficient or excessive intake of carbohydrate and fat. The mean probability of adequacy of nutrient intakes was low (0.33) and not different across all three occupational groups except for folate, which favored workers. Our study provides novel evidence supporting the development and implementation of interventions to achieve national targets, with emphasis on female youths who undergo special transitions in education, occupation, and lifestyle.

Individual-based analyses reveal effects of behavioral and demographic variables associated with multi-annual reproductive success of male and female lake sturgeon.

Quantifying effects of individual attributes and population demographic characteristics that affect inter- and intrasexual interactions and adult reproductive success, and the spatial and temporal contexts in which they are expressed is important to effective species management. Multi-year individual-based analyses using genetically determined parentage allowed the examination of variables associated with the reproductive success of male and female lake sturgeon (Acipenser fulvescens) in the well-studied population in Black Lake, Michigan, USA. Spawning lake sturgeon (a total of 599 individuals where many were captured more than once based on 1024 total captures) and larvae (N = 3436) were genotyped during each of seven consecutive years (2001-2007). Factors associated with individual reproductive success differed between sexes and varied among spawning groups within a year and among years depending on spawning date (higher reproductive success earlier in the season for females) and spawning locations (higher reproductive success in upstream spawning zones for females). Female reproductive success increased nonlinearly with increasing body size. Male reproductive success increased with increasing residence time in spawning areas and, to a modest degree, with increasing body size in a nonlinear fashion. Fixed effects of repeatability in spawn timing and location across years led to consistently higher or lower reproductive success for females. Results identified factors, including time spent at spawning areas by males and intersexual encounters and mate number, that contributed to higher interindividual variance in reproductive success and affected population levels of recruitment, the degree of subpopulation genetic structure (lack of isolation by time), and effective population size.

Sexual dimorphism and reproductive biology of Cephalocassis borneensis (Siluriformes: Ariidae), a paternal mouth-brooding fish in the Mekong River.

Information on the reproductive biology of fish species is essential for fisheries management, conservation and culture potential assessment. Therefore, this study aimed to understand the sex-based morphological differences and reproductive characteristics of Cephalocassis borneensis, an ariid species with a rapid decline of wild populations. Fish samples were collected monthly from local fishermen (n = 1092) in the Vietnamese Mekong River over a year. Morphological analyses revealed that sexual dimorphism was observed in mature, but not immature, fish. The length at first maturity (Lm ) was smaller for males (11.5 cm) than for females (12.5 cm). Mature males had larger head length and pre-pectoral distance than mature females, increasing the space for oral incubation of fertilized eggs and larvae in males. Conversely, females were larger in three head parameters (head angle, head width and head depth) and three abdomen parameters (body deep, ventral fin length and distance between pectoral and ventral fin) involved in ovary development. Paternal mouth-brooding behaviour is an important reproductive strategy in C. borneensis to increase offspring survival. Monthly variations in gonado-somatic index and condition factor (K) and the presence of maturation stages indicated that C. borneensis spawns year-round, mainly in the rainy season from June to October. This species' fecundity was relatively low, from 10 to 31 eggs per female of quite large sizes (about 7.30 ± 0.68 mm in diameter). Besides, non-functional oocytes (hyaline eggs) of smaller size (<3 mm) were found in the females' ovaries. Low fecundity with large eggs and paternal care indicated that the species is an equilibrium strategist. These characteristics are critical in developing ariid species conservation plans, such as setting the time and mesh-size for fishing, and domestication programmes in artificial conditions.

Spatial and temporal analysis and quantification of pollution sources of the surface water quality in a coastal province in Vietnam.

The surface water quality in coastal areas may be highly vulnerable to degradation due to various pollution sources such as seawater intrusion and anthropogenic activities. The current study sought to spatially and temporally analyze and quantify pollution sources of the surface water system in the coastal province of Tra Vinh, Vietnam. A total of 600 surface water samples were taken from 30 monitoring sites distributed over 4 spatial zones. Water samples were collected in four campaigns each year during the dry and rainy seasons from 2016 to 2020 and analyzed for 10 physiochemical and biological parameters. The analyzed data were calculated for the water quality index (WQI). Two-way analysis of variance, principal component analysis/factor analysis (PCA/FA), and multivariable regression analysis (MRA) were conducted over the whole dataset. The results showed that the WQI decreased from the inland zone to the coastal area, was greater in the river zone than in the canal zone, and was higher in the dry season than in the rainy season. The PCA/FA revealed that surface water quality was affected by at least 4 main pollution sources, including agricultural production, seawater intrusion, residential activities, and mixed sources. MRA revealed that these pollution sources explained 68.3%, 12.8%, 7.0%, and 2.7% of the total variance of the WQI, respectively. In summary, the surface water quality in the study area significantly changed spatially and temporally, depending on four pollution sources, which need to be managed properly for a better environment and sustainable development.

Multiple genetic lineages of anadromous migratory Mekong catfish Pangasius krempfi revealed by mtDNA control region and cytochrome b.

Population genetic structure of migratory fishes can reflect ecological and evolutionary processes. Pangasius krempfi is a critically important anadromous catfish in the Mekong River, and its migration pathways and genetic structure have attracted much interest. To investigate, we quantified the genetic diversity of this species using the control region (D-loop) and Cytochrome b (Cytb) of the mitochondrial genome. Fish were sampled (n = 91) along the Mekong tributaries from upstream to estuaries and coastal areas in the Mekong Delta and compared to three samples from Pakse (Laos). The D-loop haplotype (0.941 ± 0.014) and nucleotide diversity (0.0083 ± 0.0005) were high in all populations, but that of Cytb was low (0.331 ± 0.059 and 0.00063 ± 0.00011, respectively). No genetic difference was detected between populations, indicating strong gene flow and confirming a long migration distance for this species. Pangasius krempfi was not genetically structured according to geographical populations but was delineated into three haplogroups, suggesting multiple genetic lineages. The presence of haplogroups in each sampling location implies that migration downstream is random but parallel when the fish enter two river tributaries bifurcating from the main Mekong River. Individuals can also migrate along the coast, far from the estuaries, suggesting a longer migration path than previously reported, which is crucial for maintaining diverse genetic origin and migration pathways for P. krempfi.

Influence of Spin Coating and Dip Coating with Gelatin/Hydroxyapatite for Bioresorbable Mg Alloy Orthopedic Implants: In Vitro and In Vivo Studies.

Suitable biomechanical properties, good biocompatibility, and osteoconductivity of a degradable magnesium (Mg) alloy make it a potential material for orthopedic implants. The main limitation of Mg is its high corrosion rate in the human body. Surface modification is necessary to improve the Mg corrosion resistance. In this work, a polymeric layer of gelatin/nanohydroxyapatite (Gel/nHA) was coated on a ZK60 Mg alloy by dip coating and spin coating to test the corrosion resistance and biocompatibility in vitro and in vivo. The results from the in vitro test revealed that the coated groups reduced the corrosion rate with the corrosion current density by 59 and 81%, from 31.22 to 12.83 µA/cm2 and 5.83 µA/cm2 in the spin coating and dip coating groups, respectively. The dip coating group showed better corrosion resistance than the spin coating group with the lowest released hydrogen content (17.5 mL) and lowest pH value (8.23) and reducing the current density by 45%. In vitro, the relative growth rate was over 75% in all groups tested with MG63, demonstrating that the Mg substrate and coating materials were within the safety range. The dip coating and spin coating groups enhanced the cell proliferation with significantly higher OD values (3.3, 3.0, and 2.5, respectively) and had better antihemolysis and antiplatelet adhesion abilities than the uncoated group. The two coating methods showed no difference in the cellular response, cell migration, hemolysis, and platelet adhesion test. In in vivo tests in rats, the dip coating group also showed a higher corrosion resistance with a lower corrosion rate and mass loss than the spin coating group. In addition, the blood biochemistry and histopathology results indicated that all materials used in this study were biocompatible with living subjects. The present research confirmed that the two methods have no noticeable difference in cell and organ response but the corrosion resistance of dip coating was higher than that of spin coating either in vitro or in vivo.

The Development of Green Bond in Developing Countries: Insights from Southeast Asia Market Participants.

Given the increasing importance of green bond as the main funding source for the Sustainable Development Goals, the green bond is an emerging concept in the region of Southeast Asia. In addition, the concurrent Covid-19 pandemic has caused disruption to the development of green bond around the world. This research explores the current development status of the green bond in Southeast Asian countries. A total of thirty-two semi-structured interviews were held with capital market participants in Southeast Asian countries. The results highlight barriers, opportunities, and regulation difficulties, and expected growth for the development of the green bond market. This research is concluded by indicating several propositions that can be tested in the future to generalize the findings from this work. We thus extend the knowledge of green bond in the financial markets of Southeast Asian countries, which also delivers implications for practitioners and policy-makers regarding the development of green bond in Southeast Asian countries.

Compte tenu de l'importance croissante de l'obligation verte en tant que principal attribut financier des objectifs de développement durable (ODD), l'obligation verte est un concept émergent dans la région de l'Asie du Sud-Est. En outre, la pandémie concomitante de Covid-19 a perturbé le développement des obligations vertes dans le monde. Cette étude explore l'état actuel du développement de l'obligation verte dans les pays d'Asie du Sud-Est. Au total, trente-deux entretiens semi-directifs ont été menés avec des acteurs du marché des capitaux dans les pays d'Asie du Sud-Est. Les résultats mettent en évidence les obstacles, les opportunités et les difficultés de réglementation, ainsi que la croissance attendue pour le développement du marché des obligations vertes. Dans sa conclusion, cette étude émet plusieurs propositions qui peuvent être testées à l'avenir pour généraliser les résultats de ce travail. Nous étoffons ainsi la connaissance concernant les obligations vertes sur les marchés financiers des pays d'Asie du Sud-Est, ce qui comporte également des implications pour les praticien·ne·s et les décisionnaires en ce qui concerne le développement des obligations vertes dans les pays d'Asie du Sud-Est.

Neuroprotective effects of total alkaloids fraction of Huperzia serrata on scopolamine-induced neurodegenerative animals.

Huperzia serrata contains Huperzine A (HupA)-an alkaloid used to treat cognitive dysfunction. In this study, we used the total alkaloids (HsAE) to investigate their potential in managing cognitive impairment in comparison with HupA. The antioxidant activity was measured by DPPH assay. In the cellular study, the cell viability and level of ACh of SH-SY5Y cells were evaluated after pretreated with HsAE and scopolamine. For in vivo assay, mice were pre-treated with HsAE, and HupA and undergone scopolamine injection for cognitive impairment. The behavioral tests including the Y-maze and Morris water maze test and the AChE activity, the SOD, CAT, MDA level in the hippocampus and cortex were evaluated. HsAE showed significant scavenging properties on DPPH radicals. HsAE was not toxic to SH-SY5Y cells, and can rescue these cells upon scopolamine treatment. Intriguingly, HsAE showed the neuroprotection against scopolamine-induced amnesia in mice. Moreover, HsAE decreased AChE activity, MDA level, increased antioxidative enzyme activity in the hippocampus as well as cortex of mice, which was relatively better than that of HupA. These findings suggested that HsAE may significantly protect the neurons of mice with scopolamine-induced memory impairment connected to AChE depletion and oxidative stress.